Hi Davie, Best thing is to do a parts check on both types (petrol & Diesel) and see if they list them as the same part number. Our old 2002 had vented discs, again a parts number check should verify. Pop your reg no herehttp://www.eurocarparts.com/car-parts?gc...oCiwrw_wcB
HTH,
Griff

Nope you don't need a new hub! You can swap and change all you like, 307 285mm discs and carriers/calipers are a good swap and not expensive, you can swap to vented 256mm discs with carriers and calipers but I'd just swap it to 285mm 307 if wheel size allows (15" steels should be fine)